1. Field of the Invention
The present invention relates to a high shelf system with a conveyor arrangement including a vertical mast structure which is movable in longitudinal direction of a corridor between shelf racks. The mast structure includes load receiving means which can be aligned with shelf compartments into which units to be stored can be inserted and from which these units can be removed. The load receiving means are displaceable perpendicularly to the shelf corridor toward and away from the shelf compartments. At least one load receiving means is fixedly arranged on the mast structure for each shelf level. At least one loading and unloading station is provided for the conveyor arrangement. The loading and unloading station serves to vertically move the units to be stored between a storage input and output level and the shelf compartments.
2. Description of the Related Art
A shelf system of the above-described type is known from German Offenlegungsschrift 33 35 289. The system has the advantage that the conveyor arrangements operate with short idle times and, thus, high material throughputs per unit of time are ensured. This is because no movements in vertical direction of the load receiving means on the conveyor arrangement are necessary, so that any resulting idle times are avoided. Since units to be stored, for example, pallets, containers, boxes, etc., can be simultaneously loaded or unloaded on each shelf level, a high material throughput is further ensured.
In this known shelf system, it is provided, on the one hand, that all load receiving means are movable by moving the mast structure perpendicularly to the shelf corridor toward the shelf compartments to be loaded. However, it is also made possible that the load receiving means provided on the mast structure can be individually moved toward the shelf compartments to be loaded.
To make possible a transfer of the units to be stored from the load receiving means to the shelf compartments or a transferring of the units from the shelf compartments to the load receiving means, the latter have special telescopic forks or grips, or they are provided with special push and pull arms which are mounted on the load receiving means so that they can be lifted and lowered for gripping and releasing the units to be stored.
Since each conveyor arrangement which is movable in longitudinal direction of the shelf corridor is used for serving both shelf racks which define the shelf corridor, the load receiving means project accordingly to both sides from the vertical mast structure. Thus, in the known shelf system, it is necessary for an optimum operation of the conveyor arrangement to provide for each load receiving means its own telescopic fork or its own telescopic grip or push and pull arms for each of the two cantilever arm sides.
Since each load receiving means is equipped on both sides with push and pull arms or with telescopic forks or grips, the conveyor arrangement is relatively cumbersome.
It is, therefore, the primary object of the present invention to provide a shelf system with a conveyor arrangement of the above-described type in which each load receiving means of the conveyor arrangement requires for serving the shelf compartments or shelf levels of two oppositely located shelf racks only one device for loading and unloading the units to be stored, for example, pallets, containers, boxes, etc., while still facilitating a high material throughput with minimum idle periods.